The present invention relates to an apparatus for detecting optical wavelength and measuring optical power. More particularly, the present invention relates to an apparatus for automatically discriminating optical wavelength provided by a light source and automatically measuring corresponding optical power.
In general, in order to maintain a multi-channel and multi-light subscriber network, it is necessary to measure the wavelength and power of a light source. Here, the light source is a multichannel light source having a prediscriminated wavelength group. The wavelength of the light source indicates the center wavelength, and the power of the light source represents the power of the light having the center wavelength.
Recently, the fiber to the home (FTTH) network has been introduced to the market, easy-to-use methods for accurately measuring wavelength and intensity of light sources have been eagerly needed for the purpose of maintenance on the FTTH network.
In the IEEE standard, the FTTH network currently uses the wavelengths with the bandwidths of 1310 nm, 1490 nm, and 1550 nm. When the optical fibers are laid or amended/restored in an optical subscriber network, it is required to measure intensity of optical signals that correspond to the center wavelength of the light source and other wavelengths and maintain the performance of the network by using the measured value.
In general, it is only possible to accurately measure the light intensity when the center wavelength of the light source is known since spectral sensitivity of the photodetector used for detecting the optical intensity depends on the wavelengths. Methods for measuring the wavelength of the light source include a method for using an additional optical spectrum analyzer and a method for using predetermined display data that are identified by color tags of optical fibers. By using the above-noted methods, the wavelengths of the light source are analyzed, a prediscriminated wavelength is selected manually, and the intensity of the selected wavelength is measured. In detail, it is controlled for the detector to detect the light of the selected wavelength by manipulating a manual wavelength selection terminal installed in the photodetector. According to the manipulation, the photodetector detects the light of the selected wavelength, outputs a corresponding electrical signal, and measures the light intensity according to the signal.
Conventionally, the center wavelength of the light source is discriminated in advance according to the user's manual manipulation by use of an additional device, the light of the discriminated center wavelength is then measured. It required a great deal of time to measure the light intensity of the center wavelength.
Also, the cost increases since an expensive optical spectrum analyzer or predetermined display data are used to discriminate the center wavelength.
In addition, errors may occur in the measured values because of manual operation since the wavelength is manually selected and the corresponding right is measured when the wavelength of the light source is discriminated.